RU2766385C1 - Wood-concrete span with composite girders from bars and reinforced concrete slab - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to construction of bridges with wood-concrete spans. Span structure is made of multi-tier girders combined with cross braces and installed on supports taking into account transverse slope, combined with monolithic reinforced concrete slab with waterproofing device and driving bed. Multilevel girders are composed of logs edged on four edges, tightly laid on each other and joined to each other along side planes by paired steel pads, dowels and bolts both in places of transverse joints, and along longitudinal seams. For joint operation of composite girders with monolithic reinforced concrete slab, upper bars of girders are equipped with bolted to them and steel paired pads with comb-like projections and flexible stops distributed with a certain interval along the span length.

EFFECT: increasing load-carrying capacity of wood-concrete span structures with composite girders from logs, reducing material consumption and labour intensity of their manufacture and installation, increasing durability and operational reliability of bridges with wood-concrete span structures.

1 cl, 4 dwg

Description

The invention relates to construction and can be used in the construction of bridges with wood-concrete spans.

A well-known design of the span structure of bridges with composite runs on lamellar dowels with metal plates made of strip steel 8-10 mm thick, installed in the slot of the connected bars [Gibshman E. E. Design of wooden bridges, ed. 2nd, revised. and additional M. "Transport", 1976, p. 66-68].

The disadvantages of the known design lie in the difficulty of ensuring the reliability of the connections associated with a careful arrangement of the slots and the fitting of the steel plates installed in them.

Close to the proposed technical essence and achieved effect design is the superstructure [patent for utility model No. 35636, superstructure with composite runs of logs and reinforced concrete slab / V.A. Utkin, V.I. Puzikov, E.Yu. Selezen // 27.01.2004], made up of multi-tiered composite girders united by cross braces and installed on supports, taking into account the transverse slope, containing logs edged into two edges, docked along the length by setting steel plates and through cylindrical dowels (bolts), interconnected along edged planes by installing mirrored comb dowel joints with cylindrical dowels rigidly fixed in steel plates and in drilled holes in logs, followed by welding of dowel plates along protruding side edges, and a reinforced concrete slab of constant thickness, concreted in place and combined for joint work with purlins by means of vertical cylindrical pins included in the upper beam of the girders and the concrete of the slab, moreover, the side walls of the outer log girders are protected from exposure to sunlight and slanting rain by screens, and the reinforced concrete slab is covered with waterproofing from mostoplast and two layers of asphalt concrete.

The disadvantage of this design lies in the complexity of the arrangement of comb-type dowel joints in the seams between rows of girders that are matched in height, in the increased compliance of deaf cylindrical dowels pinched in steel plates and immersed with their free end into drilled vertical holes, as well as in insufficient reliability of the connections of the reinforced concrete slab with girders "out of the way".

The purpose of the invention is to increase the carrying capacity of wood-concrete spans with composite girders of logs (beams), reduce the material consumption and labor intensity of their manufacture and installation, increase the durability and operational reliability of bridges with wood-concrete spans.

The specified technical result is achieved by the fact that the span, made up of combined cross-braces and installed on supports, taking into account the transverse slope of multi-tiered runs, containing logs edged on two edges, docked along the length by setting linings and through cylindrical dowels (bolts), interconnected along edged planes by installing mirror-placed comb keys with keys rigidly fixed in steel plates and in drilled holes in logs with cylindrical dowels and tie bolts, followed by welding of key plates along protruding side edges, and a reinforced concrete slab of constant thickness, concreted in place and combined for joint work with girders by means of cylindrical pins included in the upper beam of the girders and the concrete of the slab, it differs in that multi-tiered girders are made up of logs (beams) edged into four edges, tightly stacked on top of each other and united between along the side planes with paired steel plates, dowels and bolts both in the places of transverse joints and along the longitudinal seams, and for the joint operation of composite girders with a monolithic reinforced concrete slab, the upper beams of the girders are equipped with bolts attached to them and distributed at a certain interval along the length of the span steel paired plates with comb ledges and flexible stops.

A number of these differences are significant:

1. On the basis of the arrangement of joints along the longitudinal seams between the edged logs (beams) of composite runs, the connecting elements of the structures of the analog and prototype are placed directly in the seam, which requires separate careful manufacture of the mirror parts of the joints, their alignment, adjustment and, therefore, increased labor costs when combined into whole. In contrast to the prototype, the proposed solution provides for the device connections along the longitudinal seams from the side surfaces of the beams by means of paired steel plates installed symmetrically with respect to the seam by means of through cylindrical dowels and tie bolts. At the same time, for the installation and placement of connecting elements on the sides of the runs, beams were used instead of edged logs, which simplifies the connection. This method of connection significantly reduces labor costs, improves the quality of connections of composite runs and their maintenance during operation.

2. On the basis of the arrangement of connections between the composite girders and the reinforced concrete slab, in the design of the prototype, a pin connection was used, containing vertical steel cylindrical pins, installed at one end into the drilled holes in the upper surface of the composite girders, and at the other end they were concreted in a monolithic reinforced concrete slab. In contrast to the prototype for connecting composite purlins with a monolithic reinforced concrete slab, the upper beams of the purlins are provided with paired steel plates with comb ledges and flexible stops fixed to them on bolts and distributed at a certain interval along the length of the span. The proposed solution was applied in the device for combining a reinforced concrete slab with the upper chords of plank-block-nail-nail blocks [RF patent for the invention No. / V. A. Utkin, I. I. Gotovtsev //09.09.2020], which differs from the claimed solution by load-bearing wooden structures.

Thus, the claimed span structure of the bridge has a set of features that distinguish it from the prototype and known solutions and allow to achieve an increase in carrying capacity, reduce material consumption, labor intensity of manufacturing and installation, increase the durability and operational reliability of these structures.

The invention is illustrated by drawings, where in Fig. 1 shows a cross section of a span structure with composite purlins made of beams with a reinforced concrete slab, combined for joint work with overlays and through cylindrical dowels; in fig. 2 - view along A-A on the length of half the span of Fig.1; in fig. 3-4 shows a fragment of a mounting block coupled from two runs with the placement of connecting elements for combining the beams with each other and with a reinforced concrete slab.

The superstructure (figure 1-2) is composed of combined transverse ties and installed on supports, taking into account the transverse slope of multi-tiered runs 1, combined with a monolithic reinforced concrete slab 2 with a waterproofing device and a driving deck 3, while multi-tiered runs 1 are made up of bars 4, tightly stacked on top of each other and joined together along the lateral planes (Fig. 2-4) by paired steel plates 5, dowels and bolts 6 both at the transverse joints and along the longitudinal seams, and for the joint operation of composite runs with a monolithic reinforced concrete slab, the upper the beams of the purlins are equipped with steel paired plates 7 fixed to them on bolts 6 and distributed at a certain interval along the length of the span with comb protrusions 8 and flexible stops 9.

As part of the span structure, each composite run 1 works: at the first stage - on the action of its own weight and load from the concreted reinforced concrete slab 2; at the second stage, as part of a wood-concrete section - on the action of a uniformly distributed load from the roadway 3 and on the action of a temporary load in accordance with the laws of elastic distribution.

The use of composite purlins made of timber and combining them to work together with each other and with a monolithic reinforced concrete slab with paired steel plates can significantly simplify the process of manufacturing purlins, reduce the complexity of the connection device, increase their reliability and accessibility during operation through the use of through horizontal cylindrical dowels instead of vertical deaf ones. .

Claims (1)

A wood-concrete superstructure with composite girders made of beams and a reinforced concrete slab, characterized in that multi-tiered girders are made up of logs edged into four edges, tightly stacked on top of each other and joined together along the side planes by paired steel plates, dowels and bolts as in the places of transverse joints , and along the longitudinal seams, and for joint operation of composite girders with a monolithic reinforced concrete slab, the upper beams of the girders are equipped with steel paired plates with comb ledges and flexible stops fixed to them on bolts and distributed at a certain interval along the length of the span.

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